[en] The development of targeted cancer treatment adapted to individual patients requires the identification of different tumour classes according to their biology and prognosis. Gliomas are the most frequent primitive cerebral tumours and in general are divided into 2 histological subtypes: astrocytic and oligodendroglial. Most of these tumours are diffuse and infiltrating. Relapses are inevitable, with a usually fatal outcome. The histological criteria allowing the distinction between glioma tumours remain difficult to use. For about ten years, expression microarrays have been used to refine the diagnosis of gliomas and to develop a new classification. Our work focused on genetic and transcriptomic modifications that could affect the tumour behavior in a set of 30 diffuse gliomas, including astrocytomas, oligodendrogliomas, and mixed gliomas of WHO (World Health Organization) grade II and III. We linked Mapping data from Affymetrix 250k_Nsp arrays and Expression data from Affymetrix HG_U133_Plus2 arrays through a Biological Pathways analysis. The hypothesis is that common chromosomal aberrations should affect gene expression levels in commonly involved pathways. Thus, sub-classes of gliomas are defined based on statistically affected pathways and genes. Mapping studies allowed us to confirm the discriminative status of the chromosomal 1p and 19q regions for the oligodendrogliomas. Most of the chromosomal aberrations are associated with oligodendrogliomas. Astrocytomas only shared an uniparental disomy on chromosome 17p as a common aberration. We found 3 sub-groups of gliomas characterized by distinct signaling pathway alterations (more than 50% of the genes involved in those pathways are differentially ex- pressed, p-value! 0.05). These results are currently under validation by immunohistochemistry. Combining major biological parameters in a single analysis is a powerful way to create a first step of classification. Mapping studies aim to focus on interesting genomic regions. Biological pathways led us to the main genes involved, and by transcriptomics we assessed the statistical relevance of both pathways and groups of samples. These results will lead us to refine the glioma classification based on genetic pattern, and will allow us to discriminate these tumours at a new genetic level.
Disciplines :
Genetics & genetic processes
Author, co-author :
Poulet, Christophe ; Université de Liège - ULiège > Département des sciences biomédicales et précliniques > GIGA-R : Génétique humaine
Robe, Pierre ; Université de Liège - ULiège > Département des sciences biomédicales et précliniques > Département des sciences biomédicales et précliniques
This website uses cookies to improve user experience. Read more
Save & Close
Accept all
Decline all
Show detailsHide details
Cookie declaration
About cookies
Strictly necessary
Performance
Strictly necessary cookies allow core website functionality such as user login and account management. The website cannot be used properly without strictly necessary cookies.
This cookie is used by Cookie-Script.com service to remember visitor cookie consent preferences. It is necessary for Cookie-Script.com cookie banner to work properly.
Performance cookies are used to see how visitors use the website, eg. analytics cookies. Those cookies cannot be used to directly identify a certain visitor.
Used to store the attribution information, the referrer initially used to visit the website
Cookies are small text files that are placed on your computer by websites that you visit. Websites use cookies to help users navigate efficiently and perform certain functions. Cookies that are required for the website to operate properly are allowed to be set without your permission. All other cookies need to be approved before they can be set in the browser.
You can change your consent to cookie usage at any time on our Privacy Policy page.